1. Field of the Invention
The present invention relates to an apparatus for manufacturing photographic filmstrips from a long strip of photographic film, especially for manufacturing photographic filmstrips having one or two perforations and sections of data per picture frame along one or both of lateral sides thereof by perforating, recording data and cutting the long film.
2. Background Art
Leader-advancing type photographic film cassettes have been disclosed, e.g., in U.S. Pat. No. 4,846,418, in which the whole length of a filmstrip is contained within a cassette shell, and a film leader of the filmstrip can be advanced to the outside of the cassette shell by rotating a spool of the cassette. With this type of film cassette, a camera need not have the sprocket wheel that has conventionally been used for feeding the film leader to the take-up spool of the camera. Once the film leader has been engaged with the take-up spool, the filmstrip may be advanced by rotating the take-up spool. Therefore, the filmstrip of the leader-advancing type cassette need not have a lot of successive perforations which conventional 135-type filmstrips have for engagement with the sprocket wheel or the take-up spool.
Still, in order to advance the filmstrip one frame after each exposure, the filmstrip of the leader advancing type cassette has at least a perforation per picture frame. The perforation is intended to be detected by a photo-sensor in the camera to determine each frame exposure location and position it in an exposure aperture of the camera. Since these perforations for frame positioning are disposed in association with the frame exposure locations, the filmstrip of the leader advancing type cassette, hereinafter referred to as a new type filmstrip, does not have a positioning perforation in its leader and trailer where no picture frame is to be recorded. Hereinafter, a section which extends over the frame exposure locations of each individual filmstrip will be referred to as a recording section.
For providing perforations only in the recording sections of the filmstrips to be made from the long film, it is not appropriate to use a conventional perforating method for the 135-type film, such as disclosed in JPA 61-214999 and JPY 4-2800, wherein perforations are formed at constant intervals all along the long film while the long film is continuously transported.
For this reason, apparatuses for manufacturing the new type of filmstrip have been suggested, one of which uses a die set having a number of punches and dies corresponding to the number of frame exposure locations to be provided in the individual filmstrips formed from the long film. The apparatus makes the corresponding number of perforations in one punching operation in the recording section of each individual filmstrip. Hereinafter, the number of frame exposure locations per filmstrip will be referred to as the film frame number. A similar method has conventionally been applied to manufacturing 110-type filmstrips.
In FIG. 13 showing such an apparatus, the long film 12 is fed from a roll 10 to a first vacuum suction chamber 15 through a dancer roller 13 and sub-feed rollers 14. The suction chamber 15 transiently stores an appropriate length of the long film 12 before being fed to the die set 17 through a pass roller 16.
The die set 17 has a punch holder 19 with the same number of punches 18 as the film frame number, and a die plate 21 with the corresponding number of dies 20. The punches and dies 18 and 20 are arranged at the same intervals as the frame exposure locations. An air cylinder 22 is driven to move the punch holder 19 down to the die plate 21 while the long film 12 stops on the die plate 21, making the same number of perforations as the film frame number at one time.
Downstream of the die set 17 are disposed a first vacuum suction drum 24, a second vacuum suction chamber 25, a second vacuum suction drum 26, a side-printer 27 and a cutter 28 in serial fashion. The first and second suction drums 24 and 26 have suction holes formed through respective peripheral surfaces, and are driven by servo motors 30 and 32, respectively. Thus, the suction drums 24 and 26 transport the film 12 while sucking it on the peripheral surfaces thereof.
While the first suction drum 24 is driven by the servo motor 30, an encoder 31 connected to the servo motor 30 monitors the rotational amount of the drum 24 to detect the transported length of the film 12. The drum 24 starts rotating after each die-punching operation for forming the perforations P in the film 12, and stops rotating when the film 12 is transported by a unit length which is predetermined in accordance with the film frame number. Thus the next recording section to be perforated is positioned in the die set 17.
The perforated section of the film 12 is transported through the first suction drum 24 to the second suction chamber 25 to transiently store an appropriate length of the film 12 before being fed to the cutter 28. The film 12 is transported from the suction chamber 25 to the cutter 28 through the second suction drum 26, while an encoder 33 connected to the servo motor 32 monitors the rotational amount of the second suction drum 26 to detect the transported length of the film 12. The detection signal from the encoder 33 is sent to the side-printer 27.
In synchronism with the detection signal, the side-printer 27 optically records data such as the name of film manufacturer, frame serial numbers and the like as latent images of characters and bar codes along one or both of lateral sides of the film 12 while the film 12 is being transported through the second suction drum 26. The side-printer 27 is movable toward a peripheral position of the second suction drum 26 where the transported film 12 is tightly held, so that the side-printer 27 faces the photosensitive emulsion surface of the film 12 at a constant distance. The peripheral position may be referred to as a side-print position.
The second suction drum 26 stops rotating when it has transported the film 12 by the predetermined unit length. Then, the cutter 28 is actuated to cut the film 12 into individual filmstrips.
Meanwhile, the new type filmstrip may have variations in the film frame number like conventional filmstrips. To cope with the different film frame numbers, the apparatus as shown in FIG. 13 is provided with interchangeable punch holders having different numbers of punches. One of the punch holders is selected in correspondence with the film frame number of the filmstrips designated to be produced. Also the unit length for the transport of the film 12 through the suction drums 24 and 26 is changed in accordance with the selected film frame number. Although the film length extending from the die set 17 to the cutter 28 changes with the change of the unit length, the second suction chamber 25 absorbs the variation by changing the storing length of the film 12. It is to be noted that the side-print position is unchanged regardless of the film frame number. Of course, the number of times of recording as well as a side-print end position vary depending on the film frame number, as a side-print end position.
Since the above-described apparatus needs two suction drums 24 and 26, two servo motors 30 and 32, and two encoders 31 and 33 for transporting the film 12 by the unit length relative to the die set 17 and the cutter 28, respectively, its mechanism and control system are complicated. Moreover, since the drums 24 and 26 must have a diameter large enough to ensure the suction of the film 12, the distance between the cutter 28 and side-printer 27, and thus the length of the film 12 from a cut position B to the side-print position C must correspondingly be long, as is shown in FIG. 14, wherein the cut position B is a position to cut trailing ends 6 of individual filmstrips 5, that is, an innermost end in a cassette shell. However, to make use of as much area of the individual filmstrip 5 as possible, it is desirable to limit a film trailer length L3 to a range from 50 mm to 100 mm or so, wherein the film trailer length L3 represents the length from the trailing end 6 of the individual filmstrip 5 to the start of its recording section. When using the apparatus as shown in FIGS. 13 and 14, the length from the cut position B to the side-print position C is beyond the desirable trailer length L3, as is shown in FIG. 15.
To solve this problem, it is necessary in the above-described apparatus to start side-printing while the film 12 is transported through the drum 26, interrupt side-printing while the film 12 stops to be cut by the cutter 28, and restart side-printing in synchronism with the start of the next film transport. Because the transport speed of the film inevitably changes immediately before and after the film stops, side-printed images may be damaged at the interrupted portion.